Airbag apparatus

ABSTRACT

The invention relates to an airbag apparatus for motor vehicles, in particular to a side airbag apparatus comprising a gas generator ( 11 ) and a gas filling tube ( 12 ) which is connected thereto, which preferably consists of metal, which preferably is or can be laid respectively along the roof strut of the motor vehicle, which is provided along its length at predetermined distances with individual or pair-wise adjacently arranged gas outflow openings ( 13 ) and which is connected to an inflatable gas bag which extends at least over a greater portion of its length and preferably consists of individual cells, each of which is preferably associated with the or a pair of gas outflow openings ( 13 ) respectively, with the gas outflow openings ( 13 ) being formed by incisions ( 17 ) in the wall of the gas filling tube ( 12 ) which are preferably made by means of a planar tool such as a saw, and by indentations ( 18 ) of the tube wall material on one side of the incisions ( 17 ) and extending at an angle to the tube axis ( 16 ), with the indentations ( 18 ) being provided on the sides of the incisions ( 17 ) which face away from the gas generator ( 11 ) and with two incisions ( 17 ) preferably being in each case provided at a small distance transversely to the tube axis ( 16 ), the indentations ( 18 ) lying on the sides of the adjacent incisions ( 17 ) which face away from one another and the tube material between the gas outflow openings ( 13 ) being undeformed. The invention consists in that the gas generator ( 11 ) is arranged at the end region of the gas filling tube ( 12 ) in the direction towards which the limbs of the angle between each incision ( 17 ) and the tube axis ( 16 ) diverge and the maximum ( 18 ′) of the indentations ( 18 ) is displaced relative to the middle of the incisions ( 17 ) in the direction away from the gas generator ( 11 ) in such a manner that the indentations ( 18 ) have a steep flank ( 18 ″) in the end region which faces away from the gas generator ( 11 ).

[0001] The invention relates to an airbag apparatus in accordance with the preamble of claims 1, 2 or 4.

[0002] An airbag apparatus of this kind is known from EP 0 945 313, the contents of which are also included in the present application by reference.

[0003] The object of the present invention consists in creating an airbag apparatus of the initially named kind which ensures particularly favorable gas outflow relationships with good stability of the gas filling tube in the region of the gas outflow openings.

[0004] For satisfying this object a first embodiment of the invention provides the features of the characterizing part of claim 1.

[0005] Through these angle ranges, on the one hand an excellent stability of the gas filling tube in the region of the gas outflow openings and on the other hand a good gas outflow behavior are achieved.

[0006] By the solution in accordance with claim 2 the gas outflow conditions are further significantly improved without impairing the stability of the gas filling tube.

[0007] Finally, by the solution in accordance with claim 4 a gas flow direction which is particularly favorable for certain applications is achieved without the stability of the gas filling tube in the region of the gas outflow openings being impaired.

[0008] Advantageous further developments of the invention are found in claims 3 and 5 to 10.

[0009] The invention will be described in the following in more detail in an exemplary manner with reference to the drawings; shown in these are:

[0010]FIG. 1 a side view of a first embodiment of a section of a gas filling tube of an airbag apparatus in accordance with the invention,

[0011]FIG. 1a a view in the direction of the arrow I a in FIG. 1,

[0012]FIG. 2 a view of the object in FIG. 1 in the direction of the arrow II in FIG. 1,

[0013]FIG. 3 a side view of a second embodiment of a section of a gas filling tube of an airbag apparatus in accordance with the invention,

[0014]FIG. 4 a view of the object in FIG. 3 in the direction of the arrow IV in FIG. 3,

[0015]FIG. 5 a somewhat enlarged sectional view in accordance with the line V-V in FIG. 1,

[0016]FIG. 6 a somewhat enlarged sectional view in accordance with the line VI-VI in FIG. 3,

[0017]FIG. 7 a side view of a further embodiment of a section of a gas filling tube of an airbag apparatus in accordance with the invention,

[0018]FIG. 7a a view in accordance with the line VIIa in FIG. 7 and

[0019]FIG. 8 a view in accordance with the line VIII in FIG. 7.

[0020] Of the airbag apparatus in the drawings, in each case only the gas filling tube 12 is shown and the gas generator 11 is indicated. The arrangement of the constructional elements cooperating therewith, in particular of the gas bag which is inflatable through the gas outflow openings, is found in EP 0 945 313.

[0021] In accordance with FIGS. 1 and 2 two incisions 17 which are produced by a planar tool such as a saw and which in each case have an angle on the order of magnitude of +20° and −20° respectively relative to the tube axis 16 are provided in the wall of the gas filling tube 12 at a small distance in the peripheral direction. The region between the incisions 17 widens in the direction of that end of the gas filling tube 12 at which the gas generator 11, which is only indicated in broken lines, is arranged. Along the length of the gas filling tube 12, as many such pairs of incisions 17 are provided at a suitable distance as are required for inflating the gas bag or its cells respectively.

[0022] At the sides of the incisions 17 of each pair which face away from one another, indentations 18 are provided through a deep-draw-like deformation process, the boundary of which to the undeformed tube material is designated by 20 and of which the depth in accordance with FIG. 5 continuously increases starting from the incision ends to reach a maximum in the middle. In this way, gas outflow openings 13 are created, through which the pressure gas which is sent into the gas filling tube 12 when the gas generator 11 is ignited can flow in into the gas bag or its cells respectively.

[0023] Through the limited oblique position of the incisions 17 relative to the tube axis 16, on the one hand a relatively wide undeformed region between the adjacent incisions 17 even at their ends, which are most closely adjacent, and thereby a good tube stability is ensured and on the other hand a gas outflow amount is ensured which is matched to the requirements.

[0024] The exemplary embodiment in accordance with FIGS. 3, 4 and 6 differs from that in accordance with FIGS. 1, 2 and 5 in that the maximum 18′ of the indentations 18 is significantly displaced relative to the middle of the incisions 17 in the direction of the end of the incisions 17 which faces away from the gas generator 11 in such a manner that relatively steep flanks 18″ are formed there at which the gas which flows in the gas filling tube 12 when the gas generator 11 is ignited is deflected outwardly by a relatively large angle to the tube axis 16 into the gas bag or its cells respectively. Although these steep flanks 18″ are important for the ideal gas deflection precisely for relatively small angles of the incisions 17 relative to the tube axis 16, they can also be used to advantage at greater angles above 30°.

[0025]FIGS. 7, 7a and 8 show that the indentations 18 at adjacent incisions 17 which are arranged at an angle to the tube axis 16 can also be provided at the sides of the incisions 17 which point towards one another. In this the incisions 17 must however be oppositely angularly inclined relative to the tube axis 16 as in the preceding exemplary embodiments; i.e. the incisions 17 need not diverge, but rather must converge, in the direction of the gas generator 11.

[0026] This construction and arrangement has the advantage that the two gas flows 14, 15 which emerge from adjacent gas outflow openings 13 do not enclose too great an angle with one another, thus on the whole have the same direction, which is expedient in certain uses.

[0027] In order to expedite the gas deflection, steep flanks similar to those at 18″ in FIGS. 3, 6 can also be provided in this embodiment in the end region of the indentations 18 which faces away from the gas generator 11. List of reference symbols 11 gas generator 12 gas filling tube 13 gas outflow openings 14 gas flow 15 gas flow 16 tube axis 17 incision 18 indentation 18′ maximum 18″ flank 20 boundary line 

1. Airbag apparatus for motor vehicles, in particular a side airbag apparatus comprising a gas generator (11) and a gas filling tube (12) which is connected thereto, which preferably consists of metal, which preferably is or can be laid respectively along the roof strut of the motor vehicle, which is provided along its length at predetermined distances with pairs of gas outflow openings (13) and which is connected to an inflatable gas bag which extends at least over a greater portion of its length and preferably consists of individual cells, each of which is preferably associated with a pair of gas outflow openings (13), with the gas outflow openings (13) being formed by incisions (17) in the wall of the gas filling tube (12) which are preferably made by means of a planar tool such as a saw, and by indentations (18) of the tube wall material on one side of the incisions (17) and extending at an angle to the tube axis (16), with two incisions (17) being in each case provided at a small distance transversely to the tube axis (16), the indentations (18) lying on the sides of the adjacent incisions (17) which face away from one another and the tube material between the gas outflow openings (13) being undeformed, characterized in that the incisions (17) have an angle of more than 0° to less than 30°, in particular 5° to 25°, expediently 15° to 25° and preferably about 20° to less than 30° relative to the tube axis (16) and the gas generator (11) is arranged at that end of the gas filling tube (12) in the direction towards which the limbs of the angle between the incisions (17) diverge.
 2. Airbag apparatus for motor vehicles, in particular a side airbag apparatus comprising a gas generator (11) and a gas filling tube (12) which is connected thereto, which preferably consists of metal, which preferably is or can be laid respectively along the roof strut of the motor vehicle, which is provided along its length at predetermined distances with individual or pair-wise adjacently arranged gas outflow openings (13) and which is connected to an inflatable gas bag which extends at least over a greater portion of its length and preferably consists of individual cells, each of which is preferably associated with the or a pair of gas outflow openings (13) respectively, with the gas outflow openings (13) being formed by incisions (17) in the wall of the gas filling tube (12) which are preferably made by means of a planar tool such as a saw, and by indentations (18) of the tube wall material on one side of the incisions (17) and extending at an angle to the tube axis (16), with the indentations (18) being provided on the sides of the incisions (17) which face away from the gas generator (11) and with two incisions (17) preferably being in each case provided at a small distance transversely to the tube axis (16), the indentations (18) lying on the sides of the adjacent incisions (17) which face away from one another and the tube material between the gas outflow openings (13) being undeformed, in particular in accordance with claim 1 , characterized in that the gas generator (11) is arranged at the end region of the gas filling tube (12) in the direction towards which the limbs of the angle between each incision (17) and the tube axis (16) diverge and the maximum (18′) of the indentations (18) is displaced relative to the middle of the incisions (17) in the direction away from the gas generator (11) in such a manner that the indentations (18) have a steep flank (18″) in the end region which faces away from the gas generator (11).
 3. Airbag apparatus in accordance with claim 2 , characterized in that the steep flank (18″) extends over 10% to 30%, in particular about 20% of the length of the associated incision (17).
 4. Airbag apparatus for motor vehicles, in particular a side airbag apparatus comprising a gas generator (11) and a gas filling tube (12) which is connected thereto, which preferably consists of metal, which preferably is or can be laid respectively along the roof strut of the motor vehicle, which is provided along its length at predetermined distances with individual or pair-wise adjacently arranged gas outflow openings (13) and which is connected to an inflatable gas bag which extends at least over a greater portion of its length and preferably consists of individual cells, each of which is preferably associated with the or a pair of gas outflow openings (13) respectively, with the gas outflow openings (13) being formed by incisions (17) in the wall of the gas filling tube (12) which are preferably made by means of a planar tool such as a saw, and by indentations (18) of the tube wall material on one side of the incisions (17) and extending at an angle to the tube axis (16), with the indentations (18) being provided on the sides of the incisions (17) which face away from the gas generator (11) and with two incisions (17) preferably in each case being provided at a small distance transversely to the tube axis (16) and with the tube material being undeformed between the boundary lines (20) of the indentations (18), in particular in accordance with any one of the claims 1 to 3 , characterized in that the gas generator (11) is arranged at the end region of the gas filling tube (12) in the direction towards which the limbs of the angle between each incision (17) and the tube axis (16) converge and in the case of two adjacently lying indentations (18) the indentations (18) preferably lie on the mutually facing sides of the adjacent incisions (17).
 5. Airbag apparatus in accordance with claim 4 , characterized in that the maximum of the indentations (18) is displaced relative to the middle of the incisions (17) in the direction away from the gas generator (11) in such a manner that the indentations (18) have a steep flank in the end region which faces away from the gas generator (11).
 6. Airbag apparatus in accordance with claim 4 or 5 , characterized in that the steep flank extends over 10% to 30%, in particular about 20% of the length of the associated incision (17).
 7. Airbag apparatus in accordance with any one of the claims 4 to 6 , characterized in that the angle of the incisions (17) relative to the tube axis (16) is less than 45°, in particular less than 35°.
 8. Airbag apparatus in accordance with any one of the preceding claims, characterized in that the diameter of the gas filling tube (12) lies between 12 mm and 22 mm.
 9. Airbag apparatus in accordance with any one of the preceding claims, characterized in that the minimum distance of the incisions (17) lies between 2 mm and 6 mm.
 10. Airbag apparatus in accordance with any one of the preceding claims, characterized in that the length of the incisions (17) lies between 6 mm and 15 mm. 